Industry in Ostia

Built around 12 BC, it is very well-preserved. Seating was divided into five cunei (wedges), and it could hold 2500 people. The orchestra was semi-circular. The ima cavea and media cavea survive, but the summa cavea are no longer there. The summa cavea was a later addition, built around the end of the 2nd century AD.

The theatre was in front of the Piazza of Corporations, so there was a nice view of this beautiful area for the theatre spectators. 

The stage front is decorated with alternate rectangular and semicircular niches. Three blocks of stone representing tragic theatrical masks have been placed on three plints.

The theatre was rebuilt by Commodus, and inaugurated by Septimius Severus and Caracalla in 196 AD.

Located in the middle of the Piazza of Corporations is a temple on a raised podium.

It is possibly a temple to Ceres because she is the Goddess of agriculture, including grain, and many of the businesses cited on the Piazza appear to have been connected grain distribution, and we know that this was Ostia's role generally.

Two columns stand at the top of the temple steps at the pronaos, or temple porch.

Built at the same time as the theatre, under Augustus (27 BC - 14 AD). It covers 107 x 78m. 

61 small rooms open off from the colonnade. In front of most of them are mosaics that illustrate the overseas trade business of the owners or tenants of the rooms. Many of them show images associated with the corn trade, and the most commonly mentioned province is North Africa, for example the cities of Alexandria, Sabratha, and Carthage. Others mention rope-sellers, timber shippers, ivory, and oil.

The visible mosaics are not all of the same date and were probably variously laid during the 2nd century AD. An earlier level of mosaics presumably belongs to the 1st century. 

The rooms are too small for storage of goods, so they are probably just offices where traders or their representatives (perhaps freedmen) could process orders, rather than actual shops. 

The imperial procurator in charge of the grain supply would have found it convenient to be able to contact so many traders in one place. So, it is possible that the Piazza was under imperial control. 

The Guilds/Corporations may have used the Piazza for displays and parades, maybe on religious festivals associated with Ceres and other patron Gods of the goods they dealt in. We know that they took part in imperial parades displaying their banners (vexilla collegiorum) under Gallienus and Aurelian in the 3rd century AD.

The Piazza was originally decorated with statues commemorating prominent Ostian citizens, including imperial officials and presidents of the Ostian guilds.

Quintus Calpurnius Modestus, procurator of the corn supply, was honoured with a statue set up by decree of the 'Corporation of Corn Merchants', who had probably benefited from contracts issued by him. 

Another procurator of the corn supply, Publius Bassilius Crescens, ordered his secretary to hand out gifts to the Corporation of Builders when they dedicated a statue to him. 

It had an outside wall of opus reticulatum, and there was a monumental entrance in the north part, towards the Tiber. On three sides was a covered corridor (porticus). 

During the reign of Claudius the first level was raised, and a porticus was built of one row of brick columns. Fifty rooms may have been separated by wooden partitions, but there may also have been no rooms. Mosaics were placed in the porticus, of which four have been preserved. 

The temple was erected in the centre of the Piazza during the reign of Domitian, facing the theatre. The area around the temple may have been a garden, and may have contained statues.

The level of the Piazza and the Porticus was raised some 40 centimetres during the reign of Hadrian. The entrance at the north end was closed, and the porticus was doubled. Rooms may again have been created with wooden partitions, but again this is uncertain. Some mosaics at a higher level may be contemporaneous or a later addition. 

Most mosaics at the higher level were installed later than the Hadrianic period, presumably in the reign of Commodus. In this period the porticus had over 60 rooms.

The original Claudian building consisted of four wings of storerooms around a U-shaped, colonnaded courtyard. There was a further set of storerooms in the middle. This building represents the increased commercial activity in Ostia and also the need for the Emperors to improve the grain supply.

Access was from the north, through a portico that faced the Tiber. This portico, along with the east and west walls, and the courtyard columns, were made of tufa, whereas the south wall was brick-faced concrete. This was very strong and could withstand pressure from inside. 

Under Nero, the east and west wings were doubled in size by adding extra rows of externally-facing rooms. By the late 2nd century, almost the entire building had been rebuilt at a higher level, and suspended floors had been installed to protect the grain from damp, and rodents. Stairways indicate that there was now an upper floor. 

By the reign of Severus, the north wing had been rebuilt again and raised, with suspended floors, increasing capacity. There was now only one narrow entrance in the north wall. Arches and piers were added to support the south wall. There was also a possible fire escape. 

The Warehouse was disused by the late 4th century, reflecting the loss of trade and population to Portus. 

The original Claudian warehouse could hold enough grain for 14,000 people for one year. The importance of this building (and the grain it contained) was one of the reasons why Claudius stationed a fire service nearby.

No inscriptions have been found from Ostia referring to who worked there, so the Warehouse was probably owned by the Emperor and operated by slaves and freedmen.

The headquarters of the firefighters (vigiles), was built around 117-138 AD, and restored in 207 AD. Inscriptions from the building stop at around 244, suggesting the vigiles were transferred to the increasingly important Portus. 

The plan of the barracks was simply a reworking of a design that was used for courtyard apartment blocks, and some warehouses e.g. the Great Warehouse. It looked almost entirely inwards with only slit windows facing out to the streets.

The main entrance was from the east, though there was access from the north and south too. There was an open courtyard in the middle, surrounded by a portico built on brick piers rather than columns, which was probably used for firefighting exercises, and ceremonies. 

18 rooms surrounded the portico, the use of which is mainly unknown. There was a latrine with a shrine to Fortunata in the south east corner, and bars on either side of the main entrance.

There were shops on the west side, but these were blocked up and incorporated into the barracks by the early 3rd century. Stairs led to an upper floor. 

The west side is dominated by an Augusteum (a shrine dedicated to the imperial cult), which faced the east entrance. Entering the shrine meant crossing a mosaic depicting a sacrifice of a bull and then going up a step into the shrine itself. 

Several inscribed blocks dedicated to various Emperors ranging from Antoninus Pius (138-161) to Septimius Severus (193-211), were found in there, along with various statues of Emperors.

Firefighters were sent from the Rome cohorts to serve four month tours of duty. They received a grant of state corn, and those of Latin status earned full Roman citizenship after three years in the job. The work included all-night patrols armed with axes and buckets, and operating a simple fire engine called a sipho. 

The east part of the courtyard has two large basins which may have been used in fire drills. Firefighters lived in rooms aruond the portico, and on the first floor. There is a hacked out niche in room 27. The threshold in room 51 has grooves which suggest a wheeled vehicle was in there. 

There is a geometric black and white mosaic near the main entrance, in room 2. There is a lot of graffiti in the barracks, some thanking the Emperor for a safe outcome to their work.